Devices which can be mounted on a pane of glass to enable a user to break the pane of glass in the event of an emergency are well known.
Many such devices are arranged to break only single panes of glass. Those designed to break double glazing use either a longer pin to go through both panes, making the device very big, or are built into the glass and therefore cannot be retro fitted.
GB 2,286,215 comprises a plunger having a spiked pin, surrounded by a movable collar having a second spiked pin. However this device requires the user to release the first pin to break the internal pane then push the entire device though the broken pane onto the outer pane then pull the cap back in a second action to break the outer pane.
U.S. Pat. No. 6,418,628 comprises a portable spring loaded device which although including a pair of springs and a hammer is arranged to break only a single pane of glass, especially a car window.
It is an object of the present invention to provide an improved plunger which mitigates the problem of the prior art.